Technical Field
Aspects of the present invention relate to an image forming apparatus, a method for controlling the same, and a storage medium.
Description of the Related Art
Conventionally, an image forming apparatus exists, which has no sensor for detecting the size of a document placed in a platen to suppress a cost. When a copy is made using such an image forming apparatus, the image forming apparatus sets the size of a printing sheet as the size of the document, and reads the document (see Japanese Patent Application Laid-Open No. 2009-303184). For example, as illustrated in FIG. 14A, a user instructs reading of the surface of a document 1304 with a central axis of the document 1304 adjusted to a center 1302 of a platen. Alternatively, the user instructs reading of the back of a document 1308 with a central axis of the document 1308 adjusted to the center 1302 of the platen. The image forming apparatus receiving the instruction reads an image of a region 1301 corresponding to the size of the printing sheet, and forms the read image on each of the back and surface of the sheet. As a result, as illustrated in the printing result of FIG. 14A, the formation positions of an image 1309 on the surface of the printing sheet and an image 1310 on the back thereof are aligned with the center of a sheet 1311.
Further, when the image forming apparatus has no sensor for detecting the size of the document placed in the platen, an image forming apparatus can be configured to read the document by making the document abut against the corner of the platen. Because the image forming apparatus can position the document by making the corner of the document butt against a butting position 1402 provided at the corner of the platen as illustrated in FIG. 14B, it is unnecessary for the user to adjust the central axis of the document with attention to the center of the platen.
However, when the document is smaller than the printing sheet, unless an image is read focusing on a region of the document size if the images are printed on the back and surface of the printing sheet, the printing positions of the images on the back and the surface do not match each other, which degrades appearance of the printed images. The printing result illustrated in FIG. 14B illustrates images on the surface and on the back when viewed through from the surface. The printing positions of the image on the surface and the image on the back are different from each other in the case of the printing result as illustrated, which degrades the image appearance. When a blank portion on the surface is cut off, the image on the back is cut off, which hampers convenience.
Consequently, there is a conventional method which receives information indicating the size of a document from a user before reading the document, reads the document in a region equivalent to the indicated size, and prints the document on a printing sheet. When this method is used, a blank portion does not appear in the image of the read document. Therefore, because the images of the read documents can be matched on the back and surface of the printing sheet, the position of the images on the surface and on the back do not become misaligned when the image of the document butting against the corner of the platen is formed on each of the back and surface of the printing sheet.
However, in the conventional method, the user must set the size of the document before the document is read under any circumstance.
For example, when one-sided printing is executed, it is unnecessary to care about misalignment of the images on the surface of the sheet and on the back thereof. Because the conventional method forces the user to set the size of the document even in such a case, additional work is required for the user.